Piston grooving attachment



May 1, 1962 H. E. GRAMS PISTON GROOVING ATTACHMENT File d Feb. 13, 1961 INVENTDR. Hare/a E. Grams H TTORNE Y5 fifi States P -h 3,032,334 PISTON GROOVDIG ATTACHMENT Harold E. Grams, 3230 Webber St., Saginaw, Mich. Filed Feb. 13, 1961, Ser. No. 88,748 4 Claims. (Cl. 269133) This invention relates to a piston grooving attachment and more particularly to an attachment adapted for removable connection to a rotatable chuck device and being capable of removably supporting any one of a number of different size pistons for rotation adjacent either a fixed or hand held tool that is capable of either cleaning or re-grooving the piston.

A substantial part of the business of automotive repair shops comprises the overhauling of engines and includes the cleaning and re-grooving of the grooves of a piston in which the piston rings are received. Most shops have machines equipped with rotatable chucks that are used for boring, honing or turning operations of parts other than pistons. Despite this, it has been customary heretofore for mechanics to mount pistons to be cleaned or re-grooved on stationary supports and manually rotate a tool about the periphery of the piston to clean or enlarge thegrooves. Operations of this kind require the'expenditure of a great deal of time, with the result'that the cost of engine overhauls is quite high.

' An object of thisinvention is to provide piston cleaning and re-grooving apparatus which is capable of removable attachment to machinery of the kind widely in use in automotive repair shops.

Another object of the invention is to provide a piston cleaning and re-grooving attachment which is capable of use with any one of a large number of different size pistons.

A further object of the invention is to provide piston cleaning and re-grooving apparatus of the kind referred to having a piston anchoring member that is so joined to the attachment as to provide a safeguard against damaging the piston.

Another object of the invention is to provide apparatus of the kind described which is simple in construction, economical to manufacture, and durable in use.

Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawing wherein:

FIGURE 1 is a fragmentary, isometric view of apparatus constructed in accordance with the invention, with parts being broken away to illustrate the manner in which a piston is clamped to the attachment; and

FIGURE 2 is a view partly in side elevation and partly in section.

An attachment constructed in accordance with the invention is designated generally by the reference character 1 and comprises a body member 2 having an elongated shank 3 terminating at one end in an enlarge-d, cylindrical plug 4 that is adapted to be removably inserted in a hollow chuck 5 that is journaled for rotation in a honing or other machine 6 of known construction. The chuck 5 is adapted to be rotated by an electric motor or other suitable device (not shown). The plug 4 may be equipped with a longitudinally extending slot 7 of progressively diminishing depth in a direction inwardly from the free end of the plug, the slot being adapted to receive set screws 8 or the like mounted in the chuck 5 so as removably to key the body member 2 to the chuck.

At the opposite end of the shank 3 is an enlargement 9 which terminates in an enlarged, annular flange 10 having a smooth, flat outer face 11 of a diameter larger than the diameters of pistons adapted to be associated Ice therewith. Both the flange 10 and the shank 3 of the body member are provided with aligned, axial bores 12. The bores 12 preferably are oversized so as to enable a liner 13 to be force fitted in the bores. The liner 13 preferably is formed from a material which is softer than the materials from which the pistons and body member 2 are formed, for a purpose presently to be described, but for the present it will suflice to say that the body member 2 may be an aluminum or other casting and the liner 13 may be formed of brass.

A clamp member 14 such as an eyebolt is provided and comprises an elongated stem 15 terminating at one end in a loop 16. The other end of the stem 15 is threaded so as to mate with the threads of the liner 13 and the length of the threaded portion of the stern should be such as to enable the anchor bolt to be capable of substantial movement into and out of the body member 2. In order to prevent interference between any part of the body member and that part of the loop 16 which is joined to the stem 15, the liner 13 is recessed inwardly from the face 11 of the flange so as to enable the curved portion of the loop that is joined directly to the stem 15 to be accommodated therein.

A typical piston with which the apparatus is adapted for use is designated by the reference character P and comprises an aluminum or other metal casting including a head 18 having a depending, annular skirt 19 provided with a pair of diametrally opposed openings 20 for reception of a conventional wrist pin. The peripheral edge of the skirt 19 is grooved as at 21, in a conventional manner, to receive conventional piston rings (not shown).

In the operation of the apparatus, the anchor bolt 14 will be extended from the body a distance sufiicient to enable a pin or bolt 22 to pass through both of the skirt openings 20 and through the loop 16. Thereafter, the

piston may be held manually and the chuck 5 rotated in such direction as to cause the anchor bolt to be threaded into the body member. During this operation the piston may be axially centered and this will be facilitated if the diameter of the opening of the loop 16 is somewhat greater than the diameter of the pin 22 so as to allow the latter to slide freely in the loop. After a short time, the eyebolt will have been threaded sufliciently far into the body member as to cause the piston skirt to bear against the face 11 of the flange 10 and be anchored thereagainst by the reaction of the eyebolt and the pin 22. A tool (not shown) then may be inserted in one of the grooves and the piston rotated, with the tool held stationary, so as to effect cleaning or re-grooving of the grooves. When the cleaning or re-grooving operation has been completed, the piston 19 may be rotated in the opposite direction relatively to the body member 3 so as to extend the eyebolt from the body member a distance sufficient to free the pin 22 and allow it to drop out of the openings 20. The piston 19 then may be removed and another substituted in its place and the operations repeated.

As has been pointed out, the material from which the liner 13 is made preferably is substantially softer than the material from which the other parts of the attachment or the pistons are made. The purpose of this construction is to provide a safeguard for preventing damaging a piston. For example, the application of a force on the piston suflicient to jeopardize the skirt 19 will exert a corresponding force on the bolt 14 and such force will in turn be transmitted to the threads of the liner 13. Since the material from which the liner is made is relatively soft, that material will be more inclined to yield or fail before any other material that is harder. Consequently, any breakage that is encountered ill be confined to the liner 13 which is considerably less expensive than a piston.

Because of the length of the bolt shank 15 and the eX- tent to which it is threaded, apparatus constructed in accordance with the invention is capable of use with a large number of different size pistons. Consequently, it is not necessary to provide a special attachment for pistons of varying size.

The disclosed embodiment is representative of a presently preferred form of the invention but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.

I claim:

1. An attachment for use with a rotatable driving member to support a piston for cleaning or re-grooving, said attachment comprising .a body member having means at one of its ends adapted for removable connection to said driving member and having an annular flange at its other end, said flange having a diameter greater than the diameter of pistons with which said attachment is adapted for use and having a smooth, flat outer face, said flange and said body member having aligned, axial bores therein extending from said outer face toward said one end of said body member; a liner snugly received in said bores and being formed of material that is softer than the material from which said body member is formed, said liner being axially threaded; and an adjustable anchor member having a stem threaded to mate with the threads of said liner and threadedly received in the liner, said anchor member being adapted to engage and clamp a piston against said outer face of said flange for rotation therewith.

2. An attachment for use with a rotatable driving member to support a piston for cleaning or re-grooving, said piston having a head, an annular skirt depending from said head, and a pair of openings in said skirt for removably receiving a wrist pin, said attachment comprising a body member having means at one of its ends adapted for removable connection to said driving memher and having an annular flange at its other end, said flange having a diameter greater than the diameter of the skirts of pistons with which it is adapted for use and having a smooth, flat outer face, said flangev and said body member having aligned, axial bores therein extending from said outer face toward said one end of said body member; a liner snugly received in said bores and being formed of material that is softer than the material from which said body member is formed, said liner having an axially threaded bore; and an adjustable anchor member having a stern threaded to mate with the threads of said liner and threadedly received in said liner, said anchor member having a loop fixed to said stem and adapted to receive a pin extending through said openings in said skirt so as to clamp a piston against the outer surface of said flange.

3. The construction set forth in claim 2 wherein said liner is recessed inwardly from the outer face of said flange.

4. An attachment for use with a rotatable driving member to support a piston for cleaning or re-grooving, said piston having a head, an annular skirt depending from said head, and a pair of openings in said skirt for removably receiving a wrist pin, said attachment comprising a body member having means at one of its ends adapted for removable connection to said driving member and having an annular flange at its other end, said flange having a diameter greater than the diameter of said skirt and having a smooth, fiat outer face, said flange and said body member having aligned, axial bores therein extending from said outer face toward said one end of said body member; .a liner snugly received in said bores and formed of materialthat'is softer than the materials from which said body" member and. said piston are formed, said liner being recessed inwardly from saidouter face and having an axially threaded bore; and an axially adjustableanchor member having a stem threaded over substantially. its. entire length and. threadedly received in the bore of said liner, said anchor member also having. a loop joined to said threaded stem of such size as removably to receive apin extending through the openings in said skirt so as to clamp said piston against the outer surface of said flange.

Freeman Aug. 7, 1934 Olson Nov. 6, 1951 

